Exploring Molecular and Electronic Property Predictions of Reduced Graphene Oxide Nanoflakes via Density Functional Theory

Abstract

In this research, we perform a theoretical interpretation of molecular and electronic properties of reduced graphene oxide (rGO) nanoflakes through the density functional theory. Here, two pristine graphene nanoflake systems were passivated by hydrogen atoms at their edges, armchair (C58H20) and zigzag (C54H20); besides, we implemented 12 rGO systems with a range of low oxide coverage (1, 3, and 4%). Computational calculations were carried out employing the functional hybrid B3LYP and the basis 6-31G(d, p) and 6-311G(d, p) levels of theory. We brought the proposed molecular structures to a stable minimum. We determined the global reactivity descriptors through chemical potential, hardness, softness, and index of electrophilicity. Besides, the maps of electrostatic potential were generated. We found that the hydroxyl and epoxy functional groups dope the graphene molecule in p-type and n-type forms, respectively. In addition, we could attribute the increases of the oxide coverage and the chemical potential to the softness of the molecule. These results suggest that structures with this type of doping can help in developing advanced electronics of sensors and devices.

Temperature Dependence of Electrical Conductivity and Variable Hopping Range Mechanism on Graphene Oxide Films

“…Prías-Barragán et al [36][37][38] reported a new pyrolysis method for GO single nanoplatelets and GOF synthesis from BPA with e ciencies around 90%, as well as their studies on the structural, morphological, electrical, thermal, optical, and magnetic properties 37,[39][40][41] , in addition to some potential applications, such as an IR emitter 36 , supercapacitors 42 , and optoelectronic devices 37 , among others. It has been identi ed that pyrolytic GO is a material with a polycrystalline structure, with magnetic behavior in ferromagnetism order at room temperature induced by topographic defects 43 , vibrational response of thermal insulator material (due to hydroxyl bridges) 39 , and whose multifunctional oxides give it a semiconductor electrical behavior with a narrow bandgap (0.11 to 0.30 eV) 35 .…”

Graphene Oxide: Comparisons between Experimental and Computational Simulation of HR-TEM Images

“…These methods are excellent for basic research. However, the double-thermal decomposition method in a pyrolysis system has proven to be a low-cost alternative and eco-friendly technique to synthesize stable graphene oxide multilayers, using bamboo waste products as source material at higher temperatures from 573 to 973 K; very different compared to traditional methods, as reported [41][42][43][44]. Higher temperatures promote elimination of organic compounds and oxygen functional groups, inducing formation of hydroxyl and epoxy bridges as multifunctional groups, leading to improvement in the crystal structure and positively impacting on the thermal, electrical, and magnetic transport [41][42][43][44][45][46][47][48][49][50].…”

“…The transport properties of GO can be influenced by the multilayered configuration [16] and presence of defects [17]. All these effects can be exploited in different fields [18] and applications from batteries [19][20][21][22], energy storage [23][24][25], electronics [26][27][28][29][30][31][32][33], catalysis [34], metal sorption [35], hydrogen storage [36], as well as to obtain graphene oxide monolayers [37][38][39][40][41][42][43][44], films, fibers, and membranes [45].…”

“…However, the double-thermal decomposition method in a pyrolysis system has proven to be a low-cost alternative and eco-friendly technique to synthesize stable graphene oxide multilayers, using bamboo waste products as source material at higher temperatures from 573 to 973 K; very different compared to traditional methods, as reported [41][42][43][44]. Higher temperatures promote elimination of organic compounds and oxygen functional groups, inducing formation of hydroxyl and epoxy bridges as multifunctional groups, leading to improvement in the crystal structure and positively impacting on the thermal, electrical, and magnetic transport [41][42][43][44][45][46][47][48][49][50]. Increasing temperature from 573 to 973 K leads to reduced oxygen content, from 13.0% to 5.3%, and an increment around two orders of magnitude of the electrical conductivity, as evidenced by preliminary electrical measurements performed on single nanoplatelets, as reported [41], which could be important for advanced electronics of sensors and devices [41][42][43][44][45][46].…”

“…Higher temperatures promote elimination of organic compounds and oxygen functional groups, inducing formation of hydroxyl and epoxy bridges as multifunctional groups, leading to improvement in the crystal structure and positively impacting on the thermal, electrical, and magnetic transport [41][42][43][44][45][46][47][48][49][50]. Increasing temperature from 573 to 973 K leads to reduced oxygen content, from 13.0% to 5.3%, and an increment around two orders of magnitude of the electrical conductivity, as evidenced by preliminary electrical measurements performed on single nanoplatelets, as reported [41], which could be important for advanced electronics of sensors and devices [41][42][43][44][45][46].…”